Sayyiduna Abdullah bin Qays al-Aslami (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) bought from a man of Banu Ghifar two shares at Khaybar in exchange for a slave. At the time of the sale, the Prophet (peace and blessings be upon him) said to him: Know that what we have taken from you is better than what we have given you, and as for what you are taking from me, if you wish, take it, and if you wish, leave it.
Al-Tabarani recorded it in al-Mu'jam al-Kabir via Abu Mu'awiyah from Abdullah bin Qays al-Aslami; I do not know the narrator Abu Mu'awiyah, and the rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6475